The results show: firstly, NR is product of price inelasticity of demand; Secondly, NR and SR can be substituted to a certain extent, but not completely from the perspective of the economics.

• 研究结果表明：天然橡胶属于需求缺乏弹性的商品；从经济学角度证明天然橡胶与合成橡胶在一定程度上可以相互替代。